There is a spectrum between an exclusively private enterprise economy and one that is entirely statist. It adds nothing useful to the conversation to call somebody a socialist without making explicit where on the spectrum the speaker considers true socialism to begin. And if you're going to that you might as well just criticise policy decisions on their own merits.

If you limit the definition of socialism to merely "public ownership of the means of production" then the article might have a point. But even if your knowledge on the matter consists exclusively of the relevant Wikipedia article, it's easy to see that is not the only aspect that you need to take into consideration.

I doubt it, Neither Capitalist or Socialist are against taxes, the difference is "why" and "how much". Conservatives believe we should be taxed to pay only for the services that government should provide and no more. Obama and Liberals like him believe that taxes are a tool to invoke an arbitrary form of "social justice". Social justice of course that has its roots in the socialist movement so ergo Obama can be called a socialist.